contrib/libpcap/pcap-bt-linux.c

   1 /*
   2  * Copyright (c) 2006 Paolo Abeni (Italy)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote
  15  * products derived from this software without specific prior written
  16  * permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * Bluetooth sniffing API implementation for Linux platform
  31  * By Paolo Abeni <paolo.abeni@email.it>
  32  *
  33  */
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include <config.h>
  37 #endif
  38
  39 #include "pcap-int.h"
  40 #include "pcap-bt-linux.h"
  41 #include "pcap/bluetooth.h"
  42
  43 #include <errno.h>
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include <fcntl.h>
  47 #include <string.h>
  48 #include <sys/ioctl.h>
  49 #include <sys/socket.h>
  50 #include <arpa/inet.h>
  51
  52 #include <bluetooth/bluetooth.h>
  53 #include <bluetooth/hci.h>
  54
  55 #define BT_IFACE "bluetooth"
  56 #define BT_CTRL_SIZE 128
  57
  58 /* forward declaration */
  59 static int bt_activate(pcap_t *);
  60 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  61 static int bt_inject_linux(pcap_t *, const void *, size_t);
  62 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  63 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  64
  65 /*
  66  * Private data for capturing on Linux Bluetooth devices.
  67  */
  68 struct pcap_bt {
  69         int dev_id;             /* device ID of device we're bound to */
  70 };
  71
  72 int
  73 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
  74 {
  75         struct hci_dev_list_req *dev_list;
  76         struct hci_dev_req *dev_req;
  77         int i, sock;
  78         int ret = 0;
  79
  80         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  81         if (sock < 0)
  82         {
  83                 /* if bluetooth is not supported this this is not fatal*/
  84                 if (errno == EAFNOSUPPORT)
  85                         return 0;
  86                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
  87                     errno, "Can't open raw Bluetooth socket");
  88                 return -1;
  89         }
  90
  91         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  92         if (!dev_list)
  93         {
  94                 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
  95                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  96                 ret = -1;
  97                 goto done;
  98         }
  99
 100         dev_list->dev_num = HCI_MAX_DEV;
 101
 102         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 103         {
 104                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
 105                     errno, "Can't get Bluetooth device list via ioctl");
 106                 ret = -1;
 107                 goto free;
 108         }
 109
 110         dev_req = dev_list->dev_req;
 111         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 112                 char dev_name[20], dev_descr[30];
 113
 114                 pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 115                 pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 116
 117                 /*
 118                  * Bluetooth is a wireless technology.
 119                  * XXX - if there's the notion of associating with a
 120                  * network, and we can determine whether the interface
 121                  * is associated with a network, check that and set
 122                  * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
 123                  * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
 124                  */
 125                 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str)  == NULL)
 126                 {
 127                         ret = -1;
 128                         break;
 129                 }
 130         }
 131
 132 free:
 133         free(dev_list);
 134
 135 done:
 136         close(sock);
 137         return ret;
 138 }
 139
 140 pcap_t *
 141 bt_create(const char *device, char *ebuf, int *is_ours)
 142 {
 143         const char *cp;
 144         char *cpend;
 145         long devnum;
 146         pcap_t *p;
 147
 148         /* Does this look like a Bluetooth device? */
 149         cp = strrchr(device, '/');
 150         if (cp == NULL)
 151                 cp = device;
 152         /* Does it begin with BT_IFACE? */
 153         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 154                 /* Nope, doesn't begin with BT_IFACE */
 155                 *is_ours = 0;
 156                 return NULL;
 157         }
 158         /* Yes - is BT_IFACE followed by a number? */
 159         cp += sizeof BT_IFACE - 1;
 160         devnum = strtol(cp, &cpend, 10);
 161         if (cpend == cp || *cpend != '\0') {
 162                 /* Not followed by a number. */
 163                 *is_ours = 0;
 164                 return NULL;
 165         }
 166         if (devnum < 0) {
 167                 /* Followed by a non-valid number. */
 168                 *is_ours = 0;
 169                 return NULL;
 170         }
 171
 172         /* OK, it's probably ours. */
 173         *is_ours = 1;
 174
 175         p = pcap_create_common(ebuf, sizeof (struct pcap_bt));
 176         if (p == NULL)
 177                 return (NULL);
 178
 179         p->activate_op = bt_activate;
 180         return (p);
 181 }
 182
 183 static int
 184 bt_activate(pcap_t* handle)
 185 {
 186         struct pcap_bt *handlep = handle->priv;
 187         struct sockaddr_hci addr;
 188         int opt;
 189         int             dev_id;
 190         struct hci_filter       flt;
 191         int err = PCAP_ERROR;
 192
 193         /* get bt interface id */
 194         if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
 195         {
 196                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 197                         "Can't get Bluetooth device index from %s",
 198                          handle->opt.device);
 199                 return PCAP_ERROR;
 200         }
 201
 202         /*
 203          * Turn a negative snapshot value (invalid), a snapshot value of
 204          * 0 (unspecified), or a value bigger than the normal maximum
 205          * value, into the maximum allowed value.
 206          *
 207          * If some application really *needs* a bigger snapshot
 208          * length, we should just increase MAXIMUM_SNAPLEN.
 209          */
 210         if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 211                 handle->snapshot = MAXIMUM_SNAPLEN;
 212
 213         /* Initialize some components of the pcap structure. */
 214         handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
 215         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 216
 217         handle->read_op = bt_read_linux;
 218         handle->inject_op = bt_inject_linux;
 219         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 220         handle->setdirection_op = bt_setdirection_linux;
 221         handle->set_datalink_op = NULL; /* can't change data link type */
 222         handle->getnonblock_op = pcap_getnonblock_fd;
 223         handle->setnonblock_op = pcap_setnonblock_fd;
 224         handle->stats_op = bt_stats_linux;
 225         handlep->dev_id = dev_id;
 226
 227         /* Create HCI socket */
 228         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 229         if (handle->fd < 0) {
 230                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 231                     errno, "Can't create raw socket");
 232                 return PCAP_ERROR;
 233         }
 234
 235         handle->buffer = malloc(handle->bufsize);
 236         if (!handle->buffer) {
 237                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 238                     errno, "Can't allocate dump buffer");
 239                 goto close_fail;
 240         }
 241
 242         opt = 1;
 243         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 244                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 245                     errno, "Can't enable data direction info");
 246                 goto close_fail;
 247         }
 248
 249         opt = 1;
 250         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 251                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 252                     errno, "Can't enable time stamp");
 253                 goto close_fail;
 254         }
 255
 256         /* Setup filter, do not call hci function to avoid dependence on
 257          * external libs        */
 258         memset(&flt, 0, sizeof(flt));
 259         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 260         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 261         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 262                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 263                     errno, "Can't set filter");
 264                 goto close_fail;
 265         }
 266
 267
 268         /* Bind socket to the HCI device */
 269         addr.hci_family = AF_BLUETOOTH;
 270         addr.hci_dev = handlep->dev_id;
 271 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 272         addr.hci_channel = HCI_CHANNEL_RAW;
 273 #endif
 274         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 275                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 276                     errno, "Can't attach to device %d", handlep->dev_id);
 277                 goto close_fail;
 278         }
 279
 280         if (handle->opt.rfmon) {
 281                 /*
 282                  * Monitor mode doesn't apply to Bluetooth devices.
 283                  */
 284                 err = PCAP_ERROR_RFMON_NOTSUP;
 285                 goto close_fail;
 286         }
 287
 288         if (handle->opt.buffer_size != 0) {
 289                 /*
 290                  * Set the socket buffer size to the specified value.
 291                  */
 292                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 293                     &handle->opt.buffer_size,
 294                     sizeof(handle->opt.buffer_size)) == -1) {
 295                         pcap_fmt_errmsg_for_errno(handle->errbuf,
 296                             errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
 297                         goto close_fail;
 298                 }
 299         }
 300
 301         handle->selectable_fd = handle->fd;
 302         return 0;
 303
 304 close_fail:
 305         pcap_cleanup_live_common(handle);
 306         return err;
 307 }
 308
 309 static int
 310 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
 311 {
 312         struct cmsghdr *cmsg;
 313         struct msghdr msg;
 314         struct iovec  iv;
 315         ssize_t ret;
 316         struct pcap_pkthdr pkth;
 317         pcap_bluetooth_h4_header* bthdr;
 318         u_char *pktd;
 319         int in = 0;
 320
 321         pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
 322         bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
 323         iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
 324         iv.iov_len  = handle->snapshot;
 325
 326         memset(&msg, 0, sizeof(msg));
 327         msg.msg_iov = &iv;
 328         msg.msg_iovlen = 1;
 329         msg.msg_control = handle->buffer;
 330         msg.msg_controllen = BT_CTRL_SIZE;
 331
 332         /* ignore interrupt system call error */
 333         do {
 334                 ret = recvmsg(handle->fd, &msg, 0);
 335                 if (handle->break_loop)
 336                 {
 337                         handle->break_loop = 0;
 338                         return -2;
 339                 }
 340         } while ((ret == -1) && (errno == EINTR));
 341
 342         if (ret < 0) {
 343                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 344                     errno, "Can't receive packet");
 345                 return -1;
 346         }
 347
 348         pkth.caplen = ret;
 349
 350         /* get direction and timestamp*/
 351         cmsg = CMSG_FIRSTHDR(&msg);
 352         while (cmsg) {
 353                 switch (cmsg->cmsg_type) {
 354                         case HCI_CMSG_DIR:
 355                                 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
 356                                 break;
 357                         case HCI_CMSG_TSTAMP:
 358                                 memcpy(&pkth.ts, CMSG_DATA(cmsg),
 359                                     sizeof pkth.ts);
 360                                 break;
 361                 }
 362                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 363         }
 364         if ((in && (handle->direction == PCAP_D_OUT)) ||
 365                                 ((!in) && (handle->direction == PCAP_D_IN)))
 366                 return 0;
 367
 368         bthdr->direction = htonl(in != 0);
 369         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 370         pkth.len = pkth.caplen;
 371         if (handle->fcode.bf_insns == NULL ||
 372             bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
 373                 callback(user, &pkth, pktd);
 374                 return 1;
 375         }
 376         return 0;       /* didn't pass filter */
 377 }
 378
 379 static int
 380 bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_)
 381 {
 382         pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 383                 "bluetooth devices");
 384         return (-1);
 385 }
 386
 387
 388 static int
 389 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 390 {
 391         struct pcap_bt *handlep = handle->priv;
 392         int ret;
 393         struct hci_dev_info dev_info;
 394         struct hci_dev_stats * s = &dev_info.stat;
 395         dev_info.dev_id = handlep->dev_id;
 396
 397         /* ignore eintr */
 398         do {
 399                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 400         } while ((ret == -1) && (errno == EINTR));
 401
 402         if (ret < 0) {
 403                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 404                     errno, "Can't get stats via ioctl");
 405                 return (-1);
 406
 407         }
 408
 409         /* we receive both rx and tx frames, so comulate all stats */
 410         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 411                 s->acl_tx +s->sco_tx;
 412         stats->ps_drop = s->err_rx + s->err_tx;
 413         stats->ps_ifdrop = 0;
 414         return 0;
 415 }
 416
 417 static int
 418 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 419 {
 420         p->direction = d;
 421         return 0;
 422 }